【发布时间】：2016-04-14 10:49:19
【问题描述】：
我正在使用这个框架：URF 和 Caliburn Micro 创建一个业务 WPF 应用程序。
这是 CM 引导程序的代码：
public class Bootstrapper : BootstrapperBase
{
private SimpleContainer container;
public Bootstrapper()
{
Initialize();
}
protected override void Configure()
{
container = new SimpleContainer();
container.Singleton<IWindowManager, WindowManager>();
container.Singleton<IEventAggregator, EventAggregator>();
container.PerRequest<IShell, ShellViewModel>();
container.AllTypesOf<ITabItem>(Assembly.GetExecutingAssembly());
container.PerRequest<IDataContextAsync, AuraContext>();
container.PerRequest<IUnitOfWorkAsync, UnitOfWork>();
container.PerRequest<IRepositoryAsync<Audit>, Repository<Audit>>();
container.PerRequest<IAuditService, AuditService>();
}
protected override object GetInstance(Type service, string key)
{
var instance = container.GetInstance(service, key);
if (instance != null)
return instance;
throw new InvalidOperationException(String.Format("Could not locate any instances of type {0}", service.Name));
}
protected override IEnumerable<object> GetAllInstances(Type serviceType)
{
return container.GetAllInstances(serviceType);
}
protected override void BuildUp(object instance)
{
container.BuildUp(instance);
}
protected override void OnStartup(object sender, StartupEventArgs e)
{
DisplayRootViewFor<IShell>();
}
}
ShellViewModel.cs 代码：
public class ShellViewModel: Conductor<ITabItem>.Collection.OneActive, IShell
{
private readonly IWindowManager _windowManager;
[ImportingConstructor]
public ShellViewModel(IWindowManager windowManager, IEnumerable<ITabItem> tabItems)
{
DisplayName = "Aura";
_windowManager = windowManager;
Items.AddRange(tabItems.Where(t => t.IsEnabled).OrderBy(t => t.DisplayOrder));
}
}
ShellView.xaml 标记：
<UserControl x:Class="Aura.ShellView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:Aura"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="600" MinWidth="800" MinHeight="600">
<TabControl x:Name="Items" Margin="3">
</UserControl>
这是一些存储库：
public static class AuditRepository
{
public static async Task<Audit> GetCurrentAudit(this IRepositoryAsync<Audit> repository)
{
var audits = await repository
.Query(a => a.BeginDate.Year == DateTime.Now.Year)
.Include()
.SelectAsync(); ;
return audits.FirstOrDefault();
}
public static IEnumerable<Reminder> GetRemindersForAudit(this IRepositoryAsync<Audit> repository, int auditId)
{
var audits = repository.GetRepository<Audit>().Queryable();
var phases = repository.GetRepository<Phase>().Queryable();
var reminders = repository.GetRepository<Reminder>().Queryable();
var query = from audit in audits
where audit.Id == auditId
join phase in phases on audit.Id equals phase.AuditId
join reminder in reminders on phase.Id equals reminder.PhaseId
select reminder;
return query.AsEnumerable();
}
}
及其服务：
public interface IAuditService: IService<Audit>
{
Task<Audit> GetCurrentAudit();
}
public class AuditService: Service<Audit>, IAuditService
{
private readonly IRepositoryAsync<Audit> _repository;
public AuditService(IRepositoryAsync<Audit> repository)
:base(repository)
{
_repository = repository;
}
public async Task<Audit> GetCurrentAudit()
{
return await _repository.GetCurrentAudit();
}
public override void Delete(Audit entity)
{
// business logic here
base.Delete(entity);
}
public override void Update(Audit entity)
{
// business logic here
base.Update(entity);
}
public override void Insert(Audit entity)
{
// business logic here
base.Insert(entity);
}
}
这是我的 ViewModels 构造函数：
[ImportingConstructor]
public AdminViewModel(
IWindowManager windowManager,
IEventAggregator eventAggregator,
IUnitOfWorkAsync unitOfWorkAsync,
IAuditService auditService)
{
_windowManager = windowManager;
_eventAggregator = eventAggregator;
_unitOfWorkAsync = unitOfWorkAsync;
_auditService = auditService
}
以及给我带来问题的 ViewModel 中的实现：
try
{
//var audits = await _unitOfWorkAsync.RepositoryAsync<Audit>().Query().SelectAsync();
//Audits = new ObservableCollection<Audit>(audits);
SelectedAudit = await _auditService.GetCurrentAudit();
//AuditHistoryHeader = String.Format(Constants.ADMINVIEW_AUDITHISTORYHEADER, Audits.Count);
SelectedAudit.ObjectState = ObjectState.Deleted;
_auditService.Delete(SelectedAudit);
_unitOfWorkAsync.SaveChanges();
var audit = _unitOfWorkAsync.Repository<Audit>().Query().Select().FirstOrDefault();
_unitOfWorkAsync.Repository<Audit>().Delete(audit);
_unitOfWorkAsync.SaveChanges();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
我在 URF UnitOfWork.cs 文件中不确定的内容：
public IRepository<TEntity> Repository<TEntity>() where TEntity : Entity, IEntity
{
try
{
if (ServiceLocator.IsLocationProviderSet)
//if (ServiceLocator.Current != null)
//{
return ServiceLocator.Current.GetInstance<IRepository<TEntity>>();
//}
}
catch (Exception)
{
}
return RepositoryAsync<TEntity>();
//return IoC.Get<IRepositoryAsync<TEntity>>();
}
问题在于，将 CRUD 操作持久保存到数据库的唯一方法是使用 _unitOfWorkAsync.Repository() 对象，而不是使用服务。
这不会失败，但数据库没有变化。我有点不确定URF 中使用的ServiceLocator 和Caliburn Micro 中的SimpleContainer 以及它们（应该）如何一起工作。我也不确定 Bootstrapper.cs 文件中容器对象的 LifeTime。
我刚刚开始了解 DI 模式，但我认为这就是我遇到的问题的原因..
如果有人已经做过类似的事情或发现问题所在，请告诉我。如果您想查看更多代码，请在下方评论。
编辑：
我尝试了以下方法，但数据没有被删除..
try
{
SelectedAudit = await _auditService.GetCurrentAudit();
SelectedAudit.ObjectState = ObjectState.Deleted;
_unitOfWorkAsync.SaveChanges();
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
如果我进入 UnitOfWork.cs SaveChanges 并查看 IDataContextAsync _dataContext Audits dbSet，则 Audit 具有 ObjectState Unchanged。所以删除的审计不是该上下文的一部分？！
【问题讨论】：
标签： c# wpf mvvm caliburn.micro unit-of-work